This invention is applicable to a wide range of gas pressure-regulating applications, but is designed for particularly advantageous use in propane outdoor cooking appliance applications. For example, the device may be used to supply an appliance with a consistent pressure in the range of 11 inches of water column when provided with inlet pressures up to 250 psig. Many conventional devices used in these applications experience three flow performance limitations that are inherent to their design. The first limitation is termed "droop, " i.e. pressure droop, which is caused by the change in the effective area of the diaphragm as it moves and the loss of load experienced by the diaphragm control spring throughout the same motion. These factors combine to cause the delivery (output) pressure to decrease as flow increases. The described invention partially overcomes this limitation by using velocity boosting to compensate. Velocity boosting subjects the diaphragm to a lower pressure than the controlled downstream pressure, which allows for a larger valve opening and higher flow rates. The second limitation, hysteresis or backlash, is partially caused by change of direction of friction forces throughout the range of motion for the device. Hysteresis causes inconsistency in the performance of such a device. The described invention reduces the effect of this limitation by providing a novel floating suspension for valving and velocity-boost components together with smoothly rounded continuous guides and slide surfaces providing essentially point-to-point controlled, low-friction contact for mechanism control. This combined with novel and improved component configurations and actuation mechanisms provides a device having novel control and operational characteristics which produce significantly enhanced performance consistency. The third limitation is caused by physical obstructions in the flow path direction. The described invention has eliminated virtually all unnecessary obstructions from the flow stream.